The invention relates to a voltage transformer for a completely insulated high-voltage switching installation comprising several conductors.
In completely insulated high-voltage switching installations containing one high-voltage conductor, it is known, for example, from the publication Smit-Mededelingen 24 (1969), pages 223 to 232, to accomplish a voltage measurement by means of an arrangement which is attached in the form of an addition on the outside of the metal encapsulation of the completely insulated high-voltage switching installation. This addition contains a rod-shaped conductor, which is connected with the high-voltage conductor and forms the high-potential electrode of the high-potential capacitor of a capacitive divider. A measuring electrode representing the other electrode of the high-potential capacitor is formed by arranging a further cylindrical electrode surrounding the rod. The measuring electrode is connected with a capacitor arranged on the outside, which forms the low-potential capacitor. An amplifier, to which a resistor forming the load is connected, is connected to the low-potential capacitor.
If a voltage transformer of this construction were used in a completely insulated high-voltage switching installation comprising several conductors, there would be incurred a very considerable additional expenditure because one external addition would have to be provided at each conductor of the high-voltage switching installation for measuring the voltage. The additions to the high-voltage switching installation would also lead to greater space requirements.